Wireless mobile communication technology uses various standards and protocols to transmit data between a transmission station and a wireless device. Some wireless devices communicate in downlink transmission using orthogonal frequency-division multiplexing (OFDM) and communicate in an uplink transmission using single-carrier frequency-division multiple access (SC-FDMA) combined with a desired digital modulation scheme via a physical layer. Standards and protocols that use OFDM include the third generation partnership project (3GPP) long term evolution (LTE), the Institute of Electrical and Electronics Engineers (IEEE) 802.16 standard (e.g., 802.16e, 802.16m), which is commonly known to industry groups as WiMAX (Worldwide interoperability for Microwave Access), and the IEEE 802.11 standard, which is commonly known to industry groups as WiFi.
In 3GPP radio access network (RAN) LTE systems, the node (e.g., a transmission station) can be a combination of Evolved Universal Terrestrial Radio Access Network (E-UTRAN) Node Bs (also commonly denoted as evolved Node Bs, enhanced Node Bs, eNodeBs, or eNBs) and Radio Network Controllers (RNCs), which communicate with a wireless device (e.g., mobile device), known as a user equipment (UE). A downlink (DL) transmission can be a communication from the node (or eNodeB) to the wireless device (or UE), and an uplink (UL) transmission can be a communication from the wireless device to the node.
In homogeneous networks, the node, also called a macro node, can provide basic wireless coverage to wireless devices in a cell. The cell can be the area in which the wireless devices are operable to communicate with the macro node. Heterogeneous networks (HetNets) are used to handle the increased traffic loads on the macro nodes due to increased usage and functionality of wireless devices. HetNets can include a layer of planned high power macro nodes (or macro-eNBs) overlaid with layers of lower power nodes (micro-eNBs, pico-eNBs, femto-eNBs, or home eNBs [HeNBs]) that can be deployed in a less well planned or even entirely uncoordinated manner within the coverage area (cell) of a macro node. The lower power nodes can generally be referred to as “low power nodes”. The macro node can be used for basic coverage, and the low power nodes can be used to fill coverage holes, to improve capacity in hot-zones or at the boundaries between the macro nodes' coverage areas, and improve indoor coverage where building structures impede signal transmission. HetNets can be used to optimize performance particularly for unequal user or traffic distribution and improve spectral efficiency (SE) per unit area of a cell. HetNets can also achieve significantly improved overall capacity and cell-edge performance.
Inter-cell interference coordination (ICIC) or enhanced ICIC (eICIC) may be used for resource coordination to reduce interference between the nodes, such as macro nodes and low power nodes. In ICIC, an interfering node (referred to as an aggressor node) may give up use of some resources in order to enable control and data transmissions between a low power node (referred to as a victim node) and a wireless device affected by interference from the aggressor node (referred to as a victim device). The nodes, such as the macro nodes and/or lower power nodes (LPN), can also be grouped together with other transmission stations in a Coordinated MultiPoint (COMP) system where transmission stations from multiple cells can transmit signals to the wireless device and receive signals from the wireless device.
Reference will now be made to the exemplary embodiments illustrated, and specific language will be used herein to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended.